首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   27篇
  免费   0篇
化学   26篇
物理学   1篇
  2006年   1篇
  1994年   8篇
  1993年   2篇
  1992年   4篇
  1991年   4篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1980年   2篇
排序方式: 共有27条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
The authors have studies the regulation of the position of substitution in 2-(4-pyridy)-1-,3-indandiones and the precise methods for introducing functionalised substitutents on teh dihydropyridine nitrogen. These N-substituted compounds can also be synthetised by (a) condensation of momo- or polymethlated pyridines on dialkyl and monoalkyl phthalates and (b) by the oxidative condensation of Nalkylpyridinium btomides on 1,3-indandione. The negative solvatochromy observed in the electronic spectra of the N-substituted 2-(1,4-dihydrp-4-pyridylidèene)-1,3-indandiones leads us to propose a betaïne structure for these compounds.  相似文献   
5.
6.
The condensation of methylated N-heterocycles and espically monomethyl- and polymethylpyridinets on phthalic enhydrides leads to 2-ary1-1,3-indanediones. The 3alklidenylphthalides formed in an intermediary state have been isloated. The influence of solvents and temperature on the velocity and yeild of formation of 2-(2- and 4-pyridyl)-1,3-indandiobnes has been studies. The ir and nmr spectra confirm taht these compunds exist under a β-diketoenamine form resonating witj a betaine form.  相似文献   
7.
8.
New conazole antifungals, in the series of triazole alcohols 23a-d and 24a-e incorporating an indole moiety substituted at 5-position by halogens, a cyano or 4-methoxyphenyl group, have been synthesized by ring opening of corresponding oxiranes 15 and 16. These dihalogeno intermediates and their congeneers could be prepared in high yields by Corey-Chaykovsky reaction under microwave irradiation.  相似文献   
9.
10.
(2-Styrylchromon-8-yl)acetic acids, structural analogs of (flavon-8-yl)acetic acid (FAA) have been synthesized with satisfactory yields according to two different methods. The 1H and 13C nmr data fovor the S-trans stereoisomers.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号